Paul introduces himself as an apostle of Jesus Christ and warns the Galatians against turning away from the true gospel to a false one, emphasizing that justification comes through faith in Jesus Christ, not through the works of the law. He rebukes the Galatians for trying to follow the law to achieve salvation, reminding them that faith justifies people before God and that Christ has redeemed believers from the curse of the law. Paul urges the Galatians to walk by the Spirit, to crucify their flesh with its vices and desires, and to do good works towards everyone, especially those in the household of faith.